2 And after six days Jesus took with him Peter and James and John, and led them up a high mountain by themselves. And he was transfigured before them, 3 and his clothes became radiant, intensely white, as no one on earth could bleach them. 4 And there appeared to them Elijah with Moses, and they were talking with Jesus. 5 And Peter said to Jesus, “Rabbi, it is good that we are here. Let us make three tents, one for you and one for Moses and one for Elijah.” 6 For he did not know what to say, for they were terrified. 7 And a cloud overshadowed them, and a voice came out of the cloud, “This is my beloved Son; listen to him.” 8 And suddenly, looking around, they no longer saw anyone with them but Jesus only.
This event happens right after Peter recognizes Jesus as the Christ, the Messiah, the Son of God. Right after Jesus began to tell his disciples about his coming death and resurrection.
I personally believe Jesus allowed these three to be with him at this moment to strengthen their belief, their faith.
Matthew Henry's commentary states Jesus took these three to bear witness of the event, to be the record of it. But it wasn't supposed to be spread around (which will come up in tomorrow's passage). Jesus wanted a record of this, but not until after his death were they supposed to share it.
Now however, Jesus has died for our sins, he has risen from the dead, and now the world NEEDS to know now, who Jesus is.
Tomorrow's scripture focus: Mark 9:9-13